title: Repeated measurements of cerebral blood flow in the left superior temporal gyrus reveal tonic hyperactivity in patients with auditory verbal hallucinations: a possible trait marker.
abstract: BACKGROUND
  The left superior temporal gyrus (STG) has been suggested to play a key role in auditory verbal hallucinations (AVH) in patients with schizophrenia.
  
  
  METHODS
  Eleven medicated subjects with schizophrenia and medication-resistant AVH and 19 healthy controls underwent perfusion magnetic resonance (MR) imaging with arterial spin labeling (ASL). Three additional repeated measurements were conducted in the patients. Patients underwent a treatment with transcranial magnetic stimulation (TMS) between the first 2 measurements. The main outcome measure was the pooled cerebral blood flow (CBF), which consisted of the regional CBF measurement in the left STG and the global CBF measurement in the whole brain.
  
  
  RESULTS
  Regional CBF in the left STG in patients was significantly higher compared to controls (p < 0.0001) and to the global CBF in patients (p < 0.004) at baseline. Regional CBF in the left STG remained significantly increased compared to the global CBF in patients across time (p < 0.0007), and it remained increased in patients after TMS compared to the baseline CBF in controls (p < 0.0001). After TMS, PANSS (p = 0.003) and PSYRATS (p = 0.01) scores decreased significantly in patients.
  
  
  CONCLUSIONS
  This study demonstrated tonically increased regional CBF in the left STG in patients with schizophrenia and auditory hallucinations despite a decrease in symptoms after TMS. These findings were consistent with what has previously been termed a trait marker of AVH in schizophrenia.
authors.affiliation: Department of Psychiatric Neurophysiology, University Hospital of Psychiatry, University of Bern Bern, Switzerland.
authors.forename: Philipp
authors.initials: P
authors.lastname: Homan
authors.forename: Jochen
authors.initials: J
authors.lastname: Kindler
authors.forename: Martinus
authors.initials: M
authors.lastname: Hauf
authors.forename: Sebastian
authors.initials: S
authors.lastname: Walther
authors.forename: Daniela
authors.initials: D
authors.lastname: Hubl
authors.forename: Thomas
authors.initials: T
authors.lastname: Dierks
keywords: arterial spin labeling; auditory verbal hallucinations; cerebral blood flow; longitudinal study; schizophrenia; superior temporal gyrus